1. Field of the Invention
The present invention relates to a naphthalocyanine dye useful for image-forming materials, IR-sensitive thermal recording materials, optical recording devices and optical film materials, and more precisely, it relates to a novel naphthalocyanine dye having excellent absorption characteristics. The invention also relates to a method for producing the naphthalocyanine dye and a material for producing it.
2. Description of the Related Art
Phthalocyanines have been widely used as pigments, and among them, in particular, naphthalocyanine dyes have been much studied as near-IR dyes not substantially absorbing visible light but absorbing IR light (for example, see JP-A-2-296885).
Heretofore known are naphthalocyanine dyes having, on the naphthalene ring thereof, a substituent of a halogen atom, a carbon-bonding substituent (e.g., alkyl group, aryl group), an oxygen-bonding substituent (e.g., hydroxy group, alkoxy group, aryloxy group), a sulfur-bonding substituent (e.g., alkylthio group, arylthio group), a nitrogen-bonding substituent (e.g., amino group, alkylamino group), a carbonyl-bonding substituent (e.g., oxycarbonyl group, alkoxycarbonyl group), a nitrile group and a nitro group (for example, see JP-A-2-296885, Journal of Chemical Society, Parkin Transaction, I, pp. 2453-2458 (1988)); those having an acrylamido group as a polymerization precursor (for example, see JP-A-7-118723); and those having an acylamino group or its precursor (for example, see JP-A-11-152413, JP-A-11-152414 and JP-A-11-152415). However, heretofore unknown are naphthalocyanine dyes having a substituent with two divalent or trivalent hetero atoms bonding to each other.